Upon completion of the IPO, all shares of convertible preferred stock outstanding, totaling 152,665,804 shares, were automatically converted into an equivalent number of shares of Class B common stock on a one-to-one basis and their carrying value of $159.6 million was reclassified into stockholders’ equity. As of April 30, 2019, there were no shares of convertible preferred stock issued and outstanding.

In connection with the IPO, our Amended and Restated Certificate of Incorporation (COI) became effective, which authorized the issuance of 200,000,000 shares of undesignated preferred stock with a par value of $0.001 with rights and preferences, including voting rights, designated from time to time by our board of directors.

Our Amended and Restated COI also authorized the issuance of 2,000,000,000 shares of Class A common stock, $0.001 par value per share and 300,000,000 shares of Class B common stock, $0.001 par value per share. Class A and Class B common stock are referred to as common stock throughout the notes to the condensed consolidated financial statements, unless otherwise noted.

In 2011, we adopted the 2011 Global Share Plan (2011 Plan), under which officers, employees, and consultants may be granted various forms of equity incentive compensation at the discretion of the board of directors, including stock options and restricted stock awards. The awards have varying terms, but generally vest over four years, and are issued at the Fair Market Value (as defined in the 2011 Plan) of the shares of common stock on the date of grant. Certain awards provide for accelerated vesting if there is a Change in Control (as defined in the 2011 Plan). As of January 31, 2019, our board of directors had authorized 71,240,000 shares of common stock to be reserved for grants of awards under the 2011 Plan. As of January 31, 2019, stock options covering 35,064,465 shares of our Class B common stock were outstanding and the remaining number of shares available for future issuance was 1,848,100 under the 2011 Plan. In connection with the IPO, the shares of Class B common stock remaining available for issuance under the 2011 Plan became available for issuance for a corresponding number of shares of our Class A common stock under the 2019 Equity Incentive Plan (2019 Plan).

In April 2019, we adopted the 2019 Plan, which is a successor to and continuation of our 2011 Plan. Our 2019 Plan provides for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, and other forms of awards. The maximum number of shares of our Class A common stock that may be issued under our 2019 Plan will not exceed 58,300,889 shares of our Class A common stock, which is the sum of (1) 34,000,000 new shares, plus (2) an additional number of shares not to exceed 24,300,889, consisting of (A) shares that remain available for the issuance of awards under our 2011 Plan as of immediately prior to the time our 2019 Plan becomes effective and (B) shares of Class B common stock subject to outstanding stock options or other stock awards granted under our 2011 Plan that, on or after the 2019 Plan becomes effective, terminate or expire prior to exercise or settlement; are not issued because the award is settled in cash; are forfeited because of the failure to vest; or are reacquired or withheld (or not issued) to satisfy a tax withholding obligation or the purchase or exercise price, if any, as such shares become available from time to time. In addition, the number of shares of our Class A common stock reserved for issuance under our 2019 Plan will automatically increase on February 1 of each calendar year, starting on February 1, 2020 through February 1, 2029, in an amount equal to (i) 5% of the total number of shares of our common stock (both Class A and Class B) outstanding on January 31 of the fiscal year before the date of each automatic increase, or (ii) a lesser number of shares determined by our board of directors prior to the applicable February 1.

A summary of stock option activity under our equity incentive plan and related information is as follows:

	Options Outstanding
						Weighted-
				Weighted-		Average
	Outstanding			Average		Remaining		Aggregate
	Stock			Exercise		Contractual		Intrinsic
	Options			Price		Life (Years)		Value
	(in thousands, except share, life, and per share data)
Balance as of January 31, 2019		35,064,465		$	1.48		6.8	$	534,572
Granted		1,324,650			27.42
Exercised		(13,622,754	)		0.14
Cancelled/forfeited/expired		(142,301	)		4.60
Balance as of April 30, 2019		22,624,060		$	3.78		8.2	$	1,554,000
Vested as of April 30, 2019		7,516,678		$	0.76		7.1	$	539,010

As of April 30, 2019, unrecognized stock-based compensation expense related to outstanding unvested stock options was $93.6 million, which is expected to be recognized over a weighted-average period of 3.4 years.

In April 2019, we adopted the 2019 Employee Stock Purchase Plan (ESPP), which became effective in connection with the IPO. A total of 9,000,000 shares of our Class A common stock were initially reserved for issuance under the ESPP. The number of shares of our Class A common stock reserved for issuance will automatically increase on February 1 of each calendar year, beginning on February 1, 2020 through February 1, 2029, by the lesser of (1) 1% of the total number of shares of our common stock (both Class A and Class B) outstanding on the last day of the fiscal year before the date of the automatic increase, and (2) 7,500,000 shares; provided that before the date of any such increase, our board of directors may determine that such increase will be less than the amount set forth in clauses (1) and (2).

Generally, all regular employees, including executive officers, employed by us or by any of our designated affiliates, except for those holding five percent or more of the total combined voting power or value of all classes of our stock, may participate in the ESPP and may contribute, normally through payroll deductions, up to 20% of their earnings (as defined in the ESPP) for the purchase of our Class A common stock under the ESPP. Unless otherwise determined by our board of directors, Class A common stock will be purchased for the accounts of employees participating in the ESPP at a price per share that is at least the lesser of (1) 85% of the fair market value of a share of our Class A common stock on the first date of an offering, or (2) 85% of the fair market value of a share of our Class A common stock on the date of purchase. No employee may purchase shares under the ESPP at a rate in excess of $25,000 worth of our Class A common stock based on the fair market value per share of our Class A common stock at the beginning of an offering for each calendar year such purchase right is outstanding. The initial offering period began on April 18, 2019. As of April 30, 2019, no shares of our Class A common stock have been purchased under the ESPP.

Our board of directors authorized certain stock option holders to exercise unvested options to purchase shares of common stock. Shares received from such early exercises are subject to repurchase in the event of the optionee’s termination of service, at the original issuance price, until the options are fully vested. As of April 30, 2019 and January 31, 2019, 697,564 and 1,261,230 shares of Class B common stock were subject to repurchase at a weighted-average price of $2.59 and $1.41 per share, respectively. As of April 30, 2019 and January 31, 2019, the cash proceeds received for unvested shares of common stock recorded within accrued expenses and other current liabilities in the condensed consolidated balance sheets were $1.8 million and $1.8 million, respectively.

In October 2015, we issued 1,202,720 shares of common stock to a member of our board of directors under a restricted stock agreement at a grant date fair value of $0.14 per share, totaling $0.2 million. Of the total shares issued, 481,088 shares vested on the grant date and the remaining shares vest over four years from the grant date. The unvested shares are subject to a repurchase right held by us at the original purchase price. As of April 30, 2019, 180,408 shares of common stock were unvested and subject to repurchase.

The stock-based compensation expense by line item in the accompanying condensed consolidated statements of operations is summarized as follows:

	Three Months Ended April 30,
	2019		2018
	(in thousands)
Cost of revenue	$	830	$	95
Research and development		1,164		129
Sales and marketing		2,627		396
General and administrative		2,041		229
Total stock-based compensation expense	$	6,662	$	849